Re: Custom ViewManager to avoid save/restore state

[Ihab Awad]

Hi again, folks,

On Sep 14, 2005, at 11:32, Ihab Awad wrote:
... I tried overriding ViewHandler methods renderView and  
restoreView to *not* call the state saving mechanism. The result is  
that I can run my app without UIComponent methods processSaveState  
or processRestoreState ever being called, which is what I want. ...  
Hence my question: do you folks see any problems with this approach?

Nobody replied yet, so I thought I'd add some more details of my  
code. Below are selected portions of my ViewHandler. This is based on  
the example from Hans Bergsten's JSF book. Again, any comments re  
this approach, especially regarding portability or possible problems  
with future JSF implementations, would be appreciated. Peace, -- Ihab

public class CustomViewHandler extends ViewHandler {

    private static final String SMD_VIEW_ID = "/smdMainView";

    private final ViewHandler origViewHandler;
    private final Map<String, UIViewRoot> smdViews = new  
HashMap<String, UIViewRoot>();

    public CustomViewHandler(ViewHandler origViewHandler) {
        this.origViewHandler = origViewHandler;
    }

    public UIViewRoot createView(FacesContext context, String viewId) {
        if (isSMDView(viewId)) {
            UIViewRoot view = customCreateView(context, viewId);
            smdViews.put(viewId, view);
            return view;
        } else {
            return origViewHandler.createView(context, viewId);
        }
    }

    public void renderView(FacesContext context, UIViewRoot  
viewToRender)
        throws IOException
    {
        if (isSMDView(viewToRender)) {
            setupResponseWriter(context);
            /**** NOTE NO STATE SAVING ****/
            context.getResponseWriter().startDocument();
            renderResponse(context, viewToRender);
            context.getResponseWriter().endDocument();
        } else {
            origViewHandler.renderView(context, viewToRender);
        }
    }

    public UIViewRoot restoreView(FacesContext context, String  
viewId) {
        if (isSMDView(viewId)) {
            /**** NOTE NO STATE RESTORATION ****/
            return smdViews.get(viewId);
        } else {
            return origViewHandler.restoreView(context, viewId);
        }
    }

    private boolean isSMDView(String viewId) {
        return viewId.startsWith(SMD_VIEW_ID);
    }

    private boolean isSMDView(UIViewRoot view) {
        return isSMDView(view.getViewId());
    }

    private UIViewRoot customCreateView(FacesContext context, String  
viewId) {

        UIViewRoot result = new UIViewRoot();

        result.setViewId(viewId);
        result.setRenderKitId(calculateRenderKitId(context));
        result.setLocale(calculateLocale(context));

        /**** NOTE CREATING INSTANCE OF MY OWN CLASS ****/
        SMDRootViewPanel rootViewPanel = new SMDRootViewPanel();
        rootViewPanel.initialize();
        result.getChildren().add(rootViewPanel);

        return result;
    }

}